Minimally invasive medical interventions are becoming increasingly important. Thus, in the treatment of coronary heart disease, for example, surgical bypass operations on the heart have declined considerably in favor of balloon dilatation (PTCA=Percutaneous Transluminal Coronary Angioplasty) and the use of a stent. Minimally invasive interventions are also increasing in the field of biopsies, spinal column treatments and tumor ablations.
In a minimally invasive intervention, one or more medical instruments for example are introduced into the body of a patient for treatment or diagnostic purposes. Following the introduction of a medical instrument into the patient's body, at least the tip of the medical instrument is no longer visible for a physician performing the intervention. In order to navigate the instrument in the body of the patient, the instrument must therefore be visualized in image information in a suitable way for the physician. Various systems and methods are available today for determining the position of the instrument in the patient's body during minimally invasive medical interventions, which is necessary for visualizing the instrument, in particular the tip of the instrument, in image information from inside the patient's body.
A challenge remaining in particular in the case of minimally invasive interventions, for example biopsies or tumor ablations, on or in regions of the patient's body that are moving e.g. due to the patient's respiratory movement is the precise introduction of the medical instrument into the body region and the accurate guiding of the medical instrument to a target tissue that is to be treated or examined. Thus, for example, a pulmonary tumor to be treated or examined can move by between 1 and 2 cm during a breathing cycle, which makes a minimally invasive medical intervention more difficult.
For that reason the patient is usually asked to hold his/her breath during a biopsy or tumor ablation so that a physician can introduce the treatment needle by hand into the tissue or organ region to be treated. Alternatively the physician can attempt to introduce the treatment needle into the tissue or organ region to be treated while estimating the respiratory cycle. In such cases the success of this procedure is usually dependent on the patient's cooperation and the physician's technical or surgical skill.